1. Field of the Invention
The invention relates to computer systems and software and, more particularly, to a graphical user interface having scroll bars which are a single pixel wide and which, under certain conditions, may be invisible.
2. Description of Related Art
Scroll bars are known in the art which are rendered as a rather wide stripe running along the border of the scrollable area. More specifically, scroll bars are typically rendered as a vertical stripe when controlling scrolling in a vertical direction and are rendered as a horizontal stripe when controlling scrolling in a horizontal direction. These are generally reasonably unobstrusive when there is no more than a single scroll bar for each direction on a display page.
Scroll bars have a scroll button (sometimes called a scroll “thumb” or “elevator”) which the user grabs in order to move the view of the display controlled by the scroll bar. When the user selects a scroll button, and drags it in a direction, the scrolling displayed within the window controlled by the scroll bar is changed in accordance with a relative position of the scroll button.
The Problems
Using traditional approaches, there is a limit as to how narrow a scroll bar can be since the user needs to be able to position the cursor over the scroll button in order to move it. In the traditional approaches, the scroll button is confined to the channel defined by the scroll bar. Therefore, as the scroll bar gets narrower, finer and finer control of the movement of the cursor is required in order to successfully grab a progressively narrower scroll button in order to move it.
As graphical user interfaces become more complex, traditional scroll bars tend to dominate too much of the visual content of the screen. This is particularly true when viewing pages on the World Wide Web and other designs which multiple scrollable areas are intermixed with other material. It would be preferable if users could concentrate on the content or on the design of the page and not have the user interface machinery take up as much screen space and visual attention as they do.